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CN-121995647-A - Off-axis superlens array-based non-screen true holographic display device and method

CN121995647ACN 121995647 ACN121995647 ACN 121995647ACN-121995647-A

Abstract

The invention relates to the technical field of non-screen true holographic display, and particularly discloses a non-screen true holographic display device and method based on an off-axis superlens array. According to the off-axis superlens array-based non-screen true hologram display device and method, the off-axis superlens is utilized to perfectly regulate and control the phase of the light beam, so that the light beam is focused off-axis in space to form a space pixel point, meanwhile, light (noise light) which is not effectively regulated and controlled by the superlens is separated in space to avoid noise light from entering a visual field, imaging quality is affected, and meanwhile, a spatial light modulator is utilized, and the on-off of the incident light beam is controlled, so that the dynamic display of the non-screen true hologram is realized.

Inventors

  • LI LI
  • LIU XINGDONG
  • WANG YU
  • TAN PENG
  • HU CHENGPENG

Assignees

  • 哈尔滨工业大学

Dates

Publication Date
20260508
Application Date
20260309

Claims (10)

  1. 1. A non-screen true holographic display device based on an off-axis super-lens array is characterized by comprising a light source module (101), a polarization regulation module, a spatial light modulator (104), an off-axis super-lens array (105), noise light (109) and a controller (108) electrically connected with the spatial light modulator (104) which are sequentially arranged on an optical path, and further comprising a light absorption element (110) arranged on a propagation path of the noise light (109); the light source module (101) is used for providing a beam of coherent and partially coherent incident light; The polarization regulation module is used for converting incident light into circularly polarized light, the polarization regulation module comprises a linear polaroid (102) and a wave plate (103) which are sequentially arranged, the linear polaroid (102) is used for carrying out polarization screening on the incident light, and the wave plate (103) is used for converting the linearly polarized light into circularly polarized light; The spatial light modulator (104) is arranged on an emergent light path of the polarization regulation module and is configured to load pattern data generated by the controller (108), and the pattern data is generated based on the spatial coordinates of the three-dimensional object (106) to be displayed and is used for allowing circularly polarized light of a corresponding area to pass through and intercepting light of other areas so as to realize light gating; The off-axis super-lens array (105) is arranged on an emergent light path of the spatial light modulator (104) and comprises a plurality of micro off-axis super-lens units (301), each super-lens unit (301) precisely corresponds to one or more pixel areas on the spatial light modulator (104) and is used for carrying out off-axis focusing on circularly polarized light passing through the corresponding area of the spatial light modulator (104) only, converging the circularly polarized light to a preset three-dimensional coordinate point in free space to form a spatial pixel (303), and simultaneously, enabling noise light (109) which is not effectively regulated to propagate along an original propagation path to realize the spatial physical separation of the signal light and the noise light (109); the controller (108) is used for cooperative computing and controlling, and comprises the steps of generating the pattern data according to the space coordinates of the three-dimensional object (106) to be displayed and loading the pattern data onto the spatial light modulator (104); The light absorbing element (110) is arranged on the main propagation path of the noise light (109), is usually in the optical axis direction and is used for absorbing the noise light (109), so that the signal-to-noise ratio of an image is improved, and clear observation of naked eyes in the observation area (107) is ensured.
  2. 2. The non-screen true holographic display device based on the off-axis super lens array of claim 1, wherein the off-axis super lens array (105) is designed to match the incident polarization state with the polarization state of circularly polarized light, the pattern data is any one of binary pattern data and gray level pattern data, the position corresponding to the space pixel (303) to be lightened in the pattern data is in a light transmission state, and the other positions are in a light shielding state.
  3. 3. The off-axis lenticular array-based, non-screen true holographic display of claim 2, further comprising lenticular elements (301), nanostructure arrays (302), spatial pixels (303), spherical waves (304) and phase planes (305), wherein the off-axis lenticular elements (105) are planar optical elements based on the super-surfaces, each micro-off-axis lenticular element (301) is composed of a sub-wavelength scale nanostructure array (302), the nanostructure arrays (302) are designed based on the PB-phase principle, for precisely compensating phase differences generated by light rays when the lenses are propagated at different positions, achieving precise regulation of the phase planes (305), enabling light rays to converge at the focal point of the spatial pixels (303) and form perfect spherical waves (304).
  4. 4. A non-screen real holographic display device based on an off-axis superlens array according to claim 3, wherein the number of micro off-axis superlens units (301) in the off-axis superlens array (105) is not less than 100 ten thousand, the preset three-dimensional coordinate points corresponding to each micro off-axis superlens unit (301) are not coincident with each other, so as to jointly form a space pixel (303) matrix of a three-dimensional image, and the matrix corresponds to the space shape of a three-dimensional object (106) reconstructed in free space, so as to ensure multi-angle observation effect in an observation area (107).
  5. 5. A non-screen true holographic display based on an off-axis superlens array according to claim 4, wherein the light absorbing element (110) comprises an adjustment seat (111): The side of the adjusting seat (111) is in threaded connection with an adjusting rod (112), the inner side of the adjusting seat (111) is in rotary connection with a light absorption shell (113), one end of the adjusting rod (112) is fixedly connected with the middle of the side of the light absorption shell (113), the inner side of the light absorption shell (113) is fixedly connected with a heat dissipation plate (117), and the side of the heat dissipation plate (117) is fixedly connected with a light absorption plate (114); a liquid cooling member (115), wherein the liquid cooling member (115) is used for radiating heat from the heat radiating plate (117), and the side surface of the liquid cooling member (115) is fixedly connected with the inner side of the heat radiating plate (117); the cleaning component (116) is used for cleaning the side face of the light absorption plate (114), and the side face of the cleaning component (116) is fixedly connected with the inner side of the light absorption shell (113); The liquid cooling component (115) comprises a radiating pipe (1151) and a water storage pipe (1153), the side of the radiating pipe (1151) is fixedly connected with the inner side of the radiating plate (117), the top of the water storage pipe (1153) is fixedly connected with a water outlet pipe (1152), the other end of the water outlet pipe (1152) is fixedly connected with the radiating pipe (1151), the top of the inner cavity of the water storage pipe (1153) is fixedly connected with a filter cartridge (1155), the bottom of the inner cavity of the water storage pipe (1153) is fixedly connected with a water pump (1157), the output end of the water pump (1157) is fixedly connected with a water inlet pipe (1154), the other end of the water inlet pipe (1154) is far away from one end of the water outlet pipe (1152) with the radiating pipe (1151), and the side of the water storage pipe (1153) is fixedly connected with a water adding pipe (1156).
  6. 6. The device of claim 5, wherein the water inlet pipe (1154) and the water outlet pipe (1152) are fixedly connected to the inner side of the light absorbing shell (113), the main propagation path of the noise light (109) is in the direction of the optical axis, the light absorbing plate (114) is any one of a black absorbing plate and a light absorbing coating, and the light absorbing shell (113) and the light absorbing plate (114) are arranged on the extension line of the optical axis and are positioned on the emergent side of the off-axis super lens array (105).
  7. 7. The screen-free real holographic display device based on the off-axis superlens array, which is disclosed in claim 6, is characterized in that the cleaning component (116) comprises a cleaning shell (1161), sliding grooves (1162) are formed in two sides of the cleaning shell (1161), a mounting frame (1163) is fixedly connected to two sides of an inner cavity of the cleaning shell (1161), an air suction machine (1164) is fixedly connected to two sides of an inner cavity of the cleaning shell (1161), a driving piece (1165) is fixedly connected to the middle part of the inner side of the cleaning shell (1161), a connecting shaft (1166) is fixedly connected to the output end of the driving piece (1165), an electrostatic dust removing rod (1167) is fixedly connected to the other end of the connecting shaft (1166) through a mounting sleeve, collecting grooves (1168) are formed in two sides of the cleaning shell (1161), meshes (1170) are formed in two sides of the collecting grooves (1168), and movable components (1169) are connected to the inner side of the collecting grooves (1168) in a sliding mode.
  8. 8. The non-screen true holographic display device based on the off-axis superlens array of claim 7, wherein the side surface of the cleaning shell (1161) is fixedly connected with the light absorption shell (113), a yielding groove is formed in the middle of the mounting frame (1163), and air grooves are formed in one side, far away from the mesh (1170), of the collecting groove (1168).
  9. 9. The non-screen true holographic display device based on the off-axis superlens array of claim 8, wherein the moving assembly (1169) comprises two moving rods (11691), two ends of each moving rod (11691) are fixedly connected with the inner side of the collecting groove (1168), a moving frame (11692) is connected to the moving rod (11691) in a sliding mode, two sides of each moving frame (11692) are connected with the inner side of the collecting groove (1168) in a sliding mode, round grooves (11695) are formed in the side faces of the moving frames (11692), feeding grooves (11693) are formed in one side, far away from the round grooves (11695), of each moving frame (11692), guide blocks (11694) are fixedly connected to the side faces of the moving frames (11692) through the round rods, and the side faces of the round rods are connected with the inner sides of the sliding grooves (1162) in a sliding mode.
  10. 10. A method of off-axis superlens array based non-screen true holographic display, according to claim 1, comprising the steps of: S1, generating pattern data, wherein a controller (108) generates pattern data defining a light transmission area on a spatial light modulator (104) according to the space coordinates of a three-dimensional object (106) to be displayed; s2, modulating polarization state, namely converting incident light emitted by a light source module (101) into circularly polarized light through a polarization regulation module; S3, gating light, namely loading the pattern data generated in the step S1 onto a spatial light modulator (104), and enabling circular polarized light to irradiate the spatial light modulator (104) so that only light energy of a light transmission area in the pattern data passes through; S4, space separation and focusing, namely, irradiating light to an off-axis super-lens array (105) through a spatial light modulator (104), and focusing partial light to a preset three-dimensional coordinate point in free space by a corresponding super-lens unit (301) in the array in an off-axis manner to form a space pixel (303), wherein noise light (109) which is not effectively regulated and controlled by the super-lens propagates along an original path and is spatially and physically separated from signal light; S5, reconstructing a non-screen image, wherein all the lightened space pixels (303) jointly form an aerial three-dimensional image which is not attached to any physical carrier and is spatially separated from noise light (109), so as to ensure clear observation in an observation area (107); s6, absorbing the noise light (109), and absorbing the noise light (109) by a light absorbing element (110) arranged on the propagation path of the noise light (109) to avoid the noise light (109) from entering the observation area (107).

Description

Off-axis superlens array-based non-screen true holographic display device and method Technical Field The invention relates to the technical field of holographic display, in particular to a non-screen true holographic display device and method based on an off-axis superlens array. Background The true holographic display technology is an advanced display technology for realizing real three-dimensional imaging of an object by relying on the interference and diffraction core principle of light, is different from a pseudo-holographic technology which relies on optical skills to simulate a stereoscopic effect, can divide a high-coherence light source into an object light wave carrying three-dimensional information of the object and a reference light wave serving as a phase reference by a light splitting means, the two beams of light form interference fringes containing all information of the amplitude and the phase of the light wave on a recording medium, when the interference fringes are reproduced, the hologram is irradiated by the reference light wave, the original object light wave front is accurately reconstructed by utilizing diffraction, a three-dimensional virtual image with complete parallax, motion parallax and real depth clues can be presented for a viewer, and the hologram has the characteristic of information redundancy, and any part of the hologram can reproduce the original object complete image. The true holographic display technology can reconstruct the complete three-dimensional light wave front of an object, and provides a final three-dimensional display experience with natural depth sense, parallax and focusing effects for users. Conventional true holographic display systems typically rely on a Spatial Light Modulator (SLM) to load a computational hologram (CGH) and achieve diffraction and imaging of light waves through complex optical lens groups, however, the prior art has many challenges: The system is huge and complex, the traditional Fourier lens group is large in size and heavy in weight, the miniaturization and integration of the system are not facilitated, the imaging quality is limited, the traditional lens has aberration, the resolution and the fidelity of a reconstructed image are reduced, the physical medium is required to be relied on, and the image cannot be carried by a physical surface or medium in the prior art, namely, the SLM, a holographic dry plate, water mist, a rotating screen and the like, so that the real 'no-screen' air suspension display cannot be realized; Inefficiency and background light pollution are the most central technical bottlenecks. Even with the novel superlens, the diffraction efficiency is difficult to reach 100%. Light which is not modulated or effectively regulated can be overlapped with useful light carrying image information, so that serious background light pollution is caused, the image signal to noise ratio is extremely low, the image is submerged in halation, and the image cannot be directly observed by naked eyes at all; Therefore, there is a strong need in the art for a technology of non-screen true holographic display that can overcome the above-mentioned drawbacks, and in particular, can solve the problem of background light pollution, thereby realizing miniaturization, high image quality, and high signal-to-noise ratio. Disclosure of Invention The invention solves the technical problems by adopting the technical scheme that the non-screen true holographic display device and the method based on the off-axis superlens array comprise a light source module, a polarization regulation module, a spatial light modulator, an off-axis superlens array, noise light and a controller electrically connected with the spatial light modulator, which are sequentially arranged on an optical path, and further comprise a light absorption element arranged on a noise light propagation path; the light source module is used for providing a beam of coherent and partially coherent incident light; the polarization regulation module is used for converting the incident light into circularly polarized light, and comprises a linear polaroid and a wave plate which are sequentially arranged, wherein the linear polaroid is used for carrying out polarization screening on the incident light, and the wave plate is used for converting the linearly polarized light into circularly polarized light; The spatial light modulator is arranged on an emergent light path of the polarization regulation module and is configured to load pattern data generated by the controller, the pattern data is generated based on the spatial coordinates of a three-dimensional object to be displayed, and the pattern data is used for allowing circularly polarized light of a corresponding area to pass through and intercepting light of other areas so as to realize light gating; The off-axis superlens array part is arranged on an emergent light path of the spatial light modulator and comprises a plurality of min